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Otter Lake in final design of $6 million upgrade
The Otter Lake Water Commission is in the final design and permitting stage of a $6,000,000 water treatment plant upgrade.
This project will include the installation of two Claricone clarifiers, two additional filters, a 500,000 baffled clearwell as well as a
new laboratory and office area for the water plant.
This project will accomplish several things for the Otter Lake Water Commission and its customers. With the addition of a new
clearwell the Commission will have a finished water storage capacity at the water plant of 1,000,000 gallons. Currently it is
500,000 gallons.
IEPA sanitary surveys have also noted the need for baffling the existing clearwell. The new clearwell will bring Otter Lake into
compliance with IEPA contact time regulations. Contact time refers to the amount of time chlorine has to react prior to the water
reaching its first customer.
Water plant capacity is measured in million gallons per day (MGD). Currently the Otter Lake Water Treatment Plant is rated at
2.7 MGD; the upgrade will raise the rating to 3.5 MGD.
The IEPA placed Otter Lake on its "watch list" because it was nearing its capacity on peak days. This plant upgrade will remove
Otter Lake from the list. Without an increase in capacity, Otter Lake could move up to the next level. This could affect its ability to
allow new taps and in theory could prevent systems receiving water from Otter Lake from allowing new taps.
The addition of two new filters, bringing the total number of filters to five, will allow the opportunity of running filters at a slower
rate. This will insure compliance with more stringent turbidity regulations. Turbidity is the measurement of the clarity of the water.
The new clarifiers will improve Otter Lakes' treatment process. The existing process was built to meet standards set in the
1960's; today's requirements are much stricter.
Claricones have been used in hundreds of water plants to meet these new standards. The process is not as mechanical as
the current process, while it is much more effective in removing turbidity before the filters. Typical reductions in chemical feeds
are in the 30% range.
Use of the clarifiers will allow a change in the treatment process. Otter Lake will be going from feeding lime as a pH adjustment
to feeding caustic soda. The conversion of Otter Lake from a lime feed plant to a turbidity removal plant will result in a cost
savings. Otter Lake feeds 1,500 pounds of lime on an average day.
This change will eliminate not only the cost of lime and other chemicals, but also almost eliminate the annual cost of removing
lime sludge, a byproduct of the current treatment process. Annual cost for lime sludge removal alone is $40,000 to $50,000.
This $6,000,000 project cannot be built without affecting rates. Otter Lake has applied for an IEPA Low Interest Loan; this loan
will have 2% to 3% interest rate and a 20 year term. The current bond, which covered the original construction of the lake and
water treatment plant, will be retired in February of 2009.
The payment for the retiring bond is $216,000 per year. Estimated payment for the low interest loan is $383,657.08, requiring
an additional $167,657.08 in revenue.
A two step rate increase has been proposed to the board. The first, a 5% increase, taking effect on October 1, 2008 with a
second 5% increase taking effect October 1, 2009.
Tours at the Otter Lake Water Treatment Plant are available by calling the office at (217) 965-1566.
The Otter Lake Water Commission is in the final design and permitting stage of a $6,000,000 water treatment plant upgrade.
This project will include the installation of two Claricone clarifiers, two additional filters, a 500,000 baffled clearwell as well as a
new laboratory and office area for the water plant.
This project will accomplish several things for the Otter Lake Water Commission and its customers. With the addition of a new
clearwell the Commission will have a finished water storage capacity at the water plant of 1,000,000 gallons. Currently it is
500,000 gallons.
IEPA sanitary surveys have also noted the need for baffling the existing clearwell. The new clearwell will bring Otter Lake into
compliance with IEPA contact time regulations. Contact time refers to the amount of time chlorine has to react prior to the water
reaching its first customer.
Water plant capacity is measured in million gallons per day (MGD). Currently the Otter Lake Water Treatment Plant is rated at
2.7 MGD; the upgrade will raise the rating to 3.5 MGD.
The IEPA placed Otter Lake on its "watch list" because it was nearing its capacity on peak days. This plant upgrade will remove
Otter Lake from the list. Without an increase in capacity, Otter Lake could move up to the next level. This could affect its ability to
allow new taps and in theory could prevent systems receiving water from Otter Lake from allowing new taps.
The addition of two new filters, bringing the total number of filters to five, will allow the opportunity of running filters at a slower
rate. This will insure compliance with more stringent turbidity regulations. Turbidity is the measurement of the clarity of the water.
The new clarifiers will improve Otter Lakes' treatment process. The existing process was built to meet standards set in the
1960's; today's requirements are much stricter.
Claricones have been used in hundreds of water plants to meet these new standards. The process is not as mechanical as
the current process, while it is much more effective in removing turbidity before the filters. Typical reductions in chemical feeds
are in the 30% range.
Use of the clarifiers will allow a change in the treatment process. Otter Lake will be going from feeding lime as a pH adjustment
to feeding caustic soda. The conversion of Otter Lake from a lime feed plant to a turbidity removal plant will result in a cost
savings. Otter Lake feeds 1,500 pounds of lime on an average day.
This change will eliminate not only the cost of lime and other chemicals, but also almost eliminate the annual cost of removing
lime sludge, a byproduct of the current treatment process. Annual cost for lime sludge removal alone is $40,000 to $50,000.
This $6,000,000 project cannot be built without affecting rates. Otter Lake has applied for an IEPA Low Interest Loan; this loan
will have 2% to 3% interest rate and a 20 year term. The current bond, which covered the original construction of the lake and
water treatment plant, will be retired in February of 2009.
The payment for the retiring bond is $216,000 per year. Estimated payment for the low interest loan is $383,657.08, requiring
an additional $167,657.08 in revenue.
A two step rate increase has been proposed to the board. The first, a 5% increase, taking effect on October 1, 2008 with a
second 5% increase taking effect October 1, 2009.
Tours at the Otter Lake Water Treatment Plant are available by calling the office at (217) 965-1566.
Issue Date: June 12, 2008
